| 摘要 |
PURPOSE:To improve operating characteristic and reliability by detecting the statical characteristics of the physical quantities of printed matter, automatically setting the discrimination levels with the first operation mode based on the statistical values, estimating the fluctuations of the apparatus from the statistical values in the second operation mode and automatically performing the correction of discrimination levels. CONSTITUTION:A detector 2 detects the quantities of, e.g., 3 color separating reflected light of printed matter 1 of discrimination symmetry and digitizes the quantities with an A/D converter 7. In the first operation mode assigned by a mode assignment switch SW12-1, an arithmetic control unit 8 obtains the mean value, dispersion, maximum value and minimum value of the respective detection quantities of N sheets of printed matter, determines the upper and lower limit discrimination levels of each detection quantity, sets the same in a discrimination level memory device 9 and sets the mean value in a statistical quantity memory device 11. In the second operation mode, the mean value of each detector of N sheets is obtained and is then compared with the storage in the memory device 11. According to the value of the difference, the contents of the memory device 9 are corrected. The contens of the apparatus 9 and the individual detection quantities are compared and discriminated in discrimination circuits 13 thru 15, whereby the overall discrimination outputs are outputted. |
